1. Field of the Invention
The present invention relates to a substrate provided with a bank and substrates provided with a color pattern such as a color filter and an electroluminescence device for use in color display device.
2. Description of the Related Art
An ink-jet method has recently been suggested as a method for fabricating a color filter for use in a color display device such as a color liquid crystal display.
Examples of methods for manufacturing a color filter by using an ink-jet process include methods described in Patent Document 1, Patent Document 2, and Patent Document 3.
Patent Document 1 describes that in order to prevent a colored ink from spreading to the outside of a desired colored region on a glass substrate, the colored ink is fixed only in the colored region by forming a pattern in which a fluorine-containing water-repellent and oil-repellent agent is introduced in advance in a bank pattern (black matrix). Further, Patent Document 2 and Patent Document 3 describe that a bank comprising a fluorine-containing compound and/or a silicon-containing compound is provided with partition walls for preventing ink bleeding and color mixing in the coloration process.
However, with the aforementioned method, due to a difference in surface energy between the bank surface and the colored ink surface, the pattern cross section easily assumes a concave or convex shape, and pixels are extremely difficult to smooth. In particular, in the case of color filters, spectral characteristics vary depending on the pixel film thickness, and a problem associated with non-uniform pixel film thickness is that color unevenness or pixel voids easily occur and display quality is degraded.
Yet another problem is that even when the content of ink-repellent agent added to the bank is reduced in order to decrease the surface energy of the bank and make the pixel film thickness more uniform, sufficient ink repellency is not maintained on the apex portions of the bank and color mixing occurs due to overflow of ink.
With the foregoing in view, it is an object of the present invention to provide an effective control method for obtaining the desired ink repellency on a bank surface in order to obtained excellent pixel smoothness and prevent color unevenness, pixel voids, and color mixing caused by overflow of ink in a substrate provided with a bank and a substrate provided with a color pattern.
Patent Document 1: JP-A-6-347637
Patent Document 2: JP-A-7-35915
Patent Document 3: JP-A-7-35917